The corrosion of metals by acids is a problem that is encountered in many industries. In the petroleum industry, for example, the corrosion of oil field tubular goods and similar equipment by hydrochloric acid solutions and other corrosive materials used in secondary oil recovery procedures and well stimulation operations has necessitated the use of inhibitors to protect corrosion of such goods and equipment against corrosion. Many different types of materials have been suggested in the past for use as corrosion inhibitors. In U.S. Pat. No. 4,028,268, for example, a multi-component inhibitor formulation is disclosed which includes certain specified quaternized cyclic nitrogen bases, specific acetylenic alcohols, a specific surface active agent and a formic acid derivative.
In U.S. Pat. No. 4,387,041, an aqueous composition for inhibiting corrosion of metals is disclosed which comprises an acid and, as a corrosion inhibitor, 3-dialkylamino-3-(substituted phenyl)-prop-1-yne.
U.S. Pat. No. 4,341,657, polymers derived from quinolines and pyridine compounds are disclosed as being useful as metal corrosion inhibitors. The polymers are referred to in the references as being polyquinolines and polypyridines, but they do not have a repeating quinoline or pyridine moiety in their respective structures.
In U.S. Pat. No. 4,676,834, there are disclosed novel compositions for use as corrosion inhibitors in servicing of oil and gas wells. Such compositions include the reaction product of quinoline, for example, with a cycloaliphatic mono-aldehyde.
Notwithstanding the teachings of the foregoing references, there has been a continuing search for new materials which are effective in inhibiting corrosion, particularly inhibiting corrosion of metals in highly acid solutions and which have a relatively high thermal stability so that they can be employed, for example, in deep drilling operations and other high temperature, corrosive environments.
In copending application Ser. No. 887,364, filed July 17, 1986 now U.S. Pat. No. 4,727,135 and incorporated herein by reference, there is disclosed a catalytic dehydrogenation process for preparing quinoline oligomers.